A smooth coated guinea pig of all one colour is known as a Self. They come in a multitude of colours, black, red, cream, white, golden, lilac, chocolate to name a few. Each colour is referred to as a separate breed, and within each colour they may also be identified by their eye colour, e.g. the pink-eyed white, and the dark-eyed white. However there is interbreeding between the colours due to the genetics of the colour genes, e.g. A buff * white mating will produce all creams, whereas a cream * cream mating will produce 50% cream, 25% buff and 25% white! The top colour is an even shade across the body, with the under colour slightly paler. All Selfs have flat faces with broad roman noses.
There are no breeds of this type currently available for sale